Which is the next two equivalent fractions of 2/3 , 5/7

Iam trying to solve a linear equation for the shoe size of someone 84" tall taking into consideration example 1 is 69" tall with a shoe size of 9 and example 2 is 72 inches tall with a shoe size of 11. i understand that the equation should be y=mx+b and that on the graph the answer is (3,2) but i just don't understand how to create the equation to solve for 84-inches and 60-inches tall questions. after two days, i need .

What is the value of x in the equation 2(x-4) = 4(2x + 1)?

Louis wants to carpet the rectangular floor of his basement. the basement has an area of 864 square feet. the width of the basement is 2/3 it's length. what is the length of louis's basement